How Vaginas Work

How Vaginas Work

In a 1993 episode of the television series "Seinfeld," Jerry finds himself unable to remember the name of the woman he's dating. When trying to get her to say it, he receives his only clue: The name rhymes with a part of the female anatomy. Jerry and his pal George Costanza consider some possibilities like Aretha and Bovary, before Jerry is forced to bite the bullet and call her Mulva to her face. As she storms out, Jerry hazards another guess -- Gipple -- but it isn't until the woman is on the street that Jerry runs to his window and yells, with gusto, "Dolores!"

The next day, a man in Wisconsin recounted the episode to a female coworker, thinking that she would find it as funny as he did. Rather than say the word "clitoris," though, he showed her the dictionary entry of the word (which, we should note, doesn't precisely rhyme with Dolores). The woman reported the man for sexual harassment, he was fired, and years of lawsuits began.

While this incident is tangled up in the thorny issue of what constitutes sexual harassment, it also speaks to our society's discomfort with women's private parts. We certainly don't hear much about vaginas on television -- in 2006, the creator of the show "Grey's Anatomy" was told that she had used the word "vagina" too much on her program, and she was asked to use a euphemism; thus, "va-jay-jay" was born [source: Rosenbloom]. The nickname was adopted by many people too uncomfortable to say the actual word. While jokes about penises are a dime a dozen, vaginas, vulvas and G-spots are considered unmentionable. Scientific researchers, perhaps operating on the principle of "out of sight, out of mind," have shunned the vagina for decades, which means we know much less about the female anatomy in comparison to the male counterparts. Even women -- the sex that actually has vaginas -- may not know much about them.

Why are vaginas so taboo? Well, the male reproductive system is obviously easier to study and understand -- the penis is outside the body, whereas much of the female reproductive system is internal. But throughout history, female sexuality has been a dangerous, forbidden thing in comparison to male sexuality. While some can accept that babies make their entrance to the world via the vagina, they may become uncomfortable when discussing how the vagina does (or does not) bring a woman sexual pleasure.

In this article, however, nothing is off limits. We'll discuss the vagina's role in human reproduction as well as its sexual function. What's normal? What's not? If you've ever wondered what's up with the area down there, read on.

External anatomy

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Vulva Anatomy

"Boys have a penis, girls have a vagina." This is often how parents describe sexual differences to their children. As a result, many of us grow up thinking that everything below a woman's waistline is her vagina, when in fact it's but one small part of the system. Though the vagina is the focus of this article, it's impossible to describe it without spending a few minutes describing everything surrounding it.

Many people say "vagina" when they're referring to a woman's external genitalia, but this area is actually the vulva. The vulva encompasses the outer and inner labia, the clitoris, the clitoral hood, the opening to the urethra and the vaginal opening.

At puberty, pubic hair starts growing on the mons, or the tissue that covers the pubic bone, as well as on the labia majora, or the outer lips. The labia majora unfold to reveal the labia minora, or inner lips; these lips are much thinner than the protective outer lips. The color and size of both sets of lips vary from woman to woman. Under the point where the inner lips meet are the clitoral hood and the clitoris. The clitoris, which is covered with more nerve endings than the penis, plays an important role in female sexual pleasure, which we'll discuss later. But researchers are learning more all the time about clitoral anatomy. The head of the clitoris, which might be the size of a pea or even a child's finger, can be seen, but it turns out that the clitoris also extends inside the body. The clitoris has a shaft that divides into two legs of tissue that extend 5 inches (12.7 cm) on each side of a woman's body. All told, the clitoris is just about the same size as the male penis.

Let's consider the head of the clitoris the engine of a nether-region train; the anus would be the caboose. The two middle cars are the urethral and vaginal openings. The urethra is the next car down from the clitoris, and while men use their penises for both urination and ejaculation, the systems are separate in women. Urine doesn't come out of the vagina; instead, the urethra connects to the bladder.

Next to the urethral opening is our star attraction for this article: the vaginal opening, which leads to the vagina.

Vaginal anatomy

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Vagina Anatomy

The vagina resembles a deflated tube that's only 2 to 4 inches (5 to 10 centimeters) long and three-fourths of an inch (1.9 cm) wide [sources: Planned Parenthood; Harrison-Hohner]. However, the vagina is lined with ringed muscular ridges so that it can expand when necessary, such as during intercourse or childbirth. During sexual intercourse, for example, the vagina swells to approximately 4 to 8 inches (10 to 20 centimeters) in length and 2.5 inches in width [sources: Planned Parenthood; Harrison-Hohner].The vagina will only expand as much as it needs to in order to hold what's inside the vagina, be it a tampon or a baby. The vagina is curved and tilts forward, toward the belly, at an angle.

The inside of the vagina features lots of bumpy tissue called rugae. It's also full of bacteria and yeast, but unless the vagina is infected, that bacteria and yeast is healthy and necessary to maintain the vaginal ecosystem. The walls of the vagina are lined with membranes that maintain a steady level of moisture in the vagina, and at the opening of the vagina are Bartholin's glands, which release additional moisture when a woman becomes sexually aroused. The vagina's wrinkly and soft appearance belies those rings of muscle that are just below the surface. Maintaining these muscles through Kegel exercises, in which a woman squeezes as if she's cutting off the flow of urine, becomes more and more important as a woman ages or gives birth.

Although the vagina expands, the majority of the nerve endings in the vagina are located near the opening, and not near the end of the tube. That means that men's agony about the length of their penis is pretty meaningless, and it also means that when the baby crowns at the opening, can be the most painful.

About .4 to .8 inches (1 to 2 centimeters) inside the vagina, some women have a thin skin tissue that covers part of the vaginal opening. This tissue is known as the hymen, or the vaginal corona. Not every woman is born with a hymen, and the skin changes form throughout a woman's life due to hormonal changes, physical activity and sexual intercourse. Because the hymen is quite a complicated piece of skin, we'll return to its existence (or lack thereof) later on in the article.

Another controversial part of the vaginal anatomy is the G-spot, which is an area of sensitive tissue located on the front wall of the vagina, about one-third or one-half the way up the canal. This area has been linked with female sexual pleasure, though researchers are bitterly divided on whether it exists or not. We'll give this much-debated spot a little more discussion when we talk about the vagina's role in intercourse.

The vagina connects to the cervix, which has a miniscule opening. Essentially, only sperm can get through that opening, so women should relinquish the fear that a runaway tampon or condom is lost forever -- it will get stuck at the cervix.

That's essentially all the vagina is -- some muscles, bumpy tissue, bacteria, and maybe a hymen and a G-spot. And yet the vagina plays important roles in human reproduction and sexual pleasure. We'll explore the vagina's function in continuing the human species on the next page.

A common worry of pregnant women is whether there will be pain when the baby exits the vagina.

The Vagina and Human Reproduction

The vagina plays an important role in human reproduction, though it's certainly not the only star of the show. While the vagina is involved in the beginning of the process -- by giving the penis a place to release sperm -- and it's certainly involved in how a baby is delivered naturally from a woman's body, the rest of the tasks fall to other organs surrounding the vagina: the ovaries, fallopian tubes, uterus and cervix.

A woman's eggs are stored in her ovaries, and each month, the ovaries release an egg that makes its way through the fallopian tubes. The uterus begins preparing itself to house a growing fetus by accumulating a lining on the walls. If the egg remains unfertilized, it is expelled, along with that uterine lining, through the cervix and then out through vagina as a menstrual period.

But let's say a woman has sexual intercourse during the time in which she is fertile, and semen makes its way from the vagina into the cervix. The sperm swim through the cervix and into the fallopian tubes; once the egg is fertilized, it makes its way into the uterus for approximately nine months of development.

Childbirth begins when the uterus starts contracting, which signals to the cervix that it must begin dilating. In other words, women aren't waiting for their vagina to stretch during hours of childbirth -- the vaginal muscles are ready at any time to expand. Once the cervix is dilated -- or, expanded far enough -- is when the baby can move through the cervix and into the vagina. Because the vagina is that last step on the baby's journey, it's often referred to as the birth canal.

It is possible, though not common, for a woman to experience vaginal tearing during childbirth. Tears are more likely to occur when a woman is having her first vaginal birth, or if she's having a vaginal birth after previously tearing. Episiotomies and bigger-than-average babies are also risk factors. There are various degrees of tearing -- nicks at the top of the vaginal canal may require stitches and cause pain for several days, while tears in vaginal muscles and perineal muscles are much more serious.

For centuries, the vagina was viewed primarily as a reproductive organ. On the next page, we'll consider the role it plays in sexual pleasure as well.

Studies suggest that learning more about how the vagina works can increase sexual pleasure for both men and women -- so consider this article homework!

The Vagina and Sexual Intercourse

When it comes to men and sex, they're pretty easy to figure out. Men's penises become erect when they're sexually aroused, and they release ejaculate when they've had an orgasm. Because women's arousal is harder to detect, and because women's orgasms aren't essential to reproduction, many people -- both men and women -- assumed that sex was something women put up with to have babies, not something that could be enjoyed.

Now, of course, there are plenty of resources, from Cosmopolitan magazine to sex therapists, who are ready to explain how a woman can gain pleasure from sex. For one thing, female arousal is now better understood. When a woman becomes sexually aroused, the labia minora become swollen and puffy, which causes salt water to push through the vaginal walls and provide lubrication. In addition, the Bartholin's glands at the vagina's entrance produce lubrication, but in both cases, that moisture is only provided for a few minutes, so additional lubrication may be needed to maintain comfort during sex.

When a woman is aroused, the clitoral hood retracts and the clitoris hardens and expands (much like an aroused penis). The clitoris is the only organ in the human body devoted solely to sensory pleasure, and it boasts 8,000 nerve endings packed into a very small space [source: Corinna]. For some women, direct contact with the clitoris can be sensory overload, and even painful, so while the clitoris is often described as a "magic button" of sorts, the button doesn't work the same way in every woman.

If you were paying attention during our vaginal anatomy section, however, you'll remember that the clitoris isn't strictly a part of the vagina, but rather located nearby. That's why you'll often hear talk of "clitoral orgasms" versus "vaginal orgasms." Some women can only experience the latter, some only the former and some women have both. A vaginal orgasm usually means that the clitoris is left out of the equation, which it often is in most sexual positions; most sex therapists advise oral or manual stimulation to effectively stimulate the clitoris.

Still, even when the external clitoris isn't being stimulated during vaginal intercourse, the internal clitoral tissue might be getting a good dose of friction. In fact, one of the reasons we spent so much time talking about the anatomy around the vagina in the first part of this article is that those areas play as much a part in sexual pleasure as the vagina does. When a penis or sex toy is inside the vagina, there can be pressure on the internal clitoris, the urethral sponge and the perineum, all of which can contribute to a woman's sexual pleasure. Pressure from another person's body, depending on the sexual position, can also add to that pleasure, and while none of these spots has as many nerve endings as the clitoris, they aren't too shabby in that count either, which means there's plenty of opportunity for a woman to experience pleasure from vaginal intercourse alone.

Many people think that the goal of vaginal intercourse is to stimulate the G-spot -- an area of tissue that has been credited with toe-curling orgasms. However, not every researcher is willing to believe it's there, no matter how many women claim otherwise. What gives? We'll investigate on the next page.

The G-Spot: Myth or Magic Button?

In the 1950s, Dr. Ernest Grafenberg wrote about a spot on the vaginal wall that was a few inches from the vaginal opening, on the side that is closest to the stomach. This area, he wrote, was capable of producing immense pleasure for a woman; the G-spot received its name in honor of that doctor. However, many researchers claim that "G" doesn't mark any spot at all.

Though women claim anecdotally to have found their G-spots, researchers have had trouble finding it consistently in lab experiments. It's possible that not every woman has one, according to Italian researcher Emmanuele Jannini. In 2002, he released a study that looked for biological and chemical changes in the tissue where the G-spot should be. He found that women who claimed to have a G-spot had a protein known as PDE5 located near the G-spot, whereas women who said they'd never had a vaginal orgasm lacked PDE5 [source: Jones]. Six years later, Jannini released another study that used ultrasound scanning to look for the G-spot. Women who reported having orgasms brought on by the G-spot showed thicker tissue in the area than women who reported never having such an orgasm [source: Sample]. Jannini suggested that his findings meant that women could have a simple test to figure out whether they had a G-spot or not; if they didn't, then the women and their partners would be able to stop worrying about finding it. Critics, however, suggested that the area might need to be developed and built up, much like a muscle that you want to do heavy lifting. If the women stopped searching for their G-spot, these critics said, then they'd never find it and fulfill their G-spot potential.

In 2010, scientists from King's College, London, claimed that there's no physical or genetic basis for the G-spot. This finding was based on a study of twins; since twins possess the same genetic makeup, researchers expected that if one twin claimed to have a G-spot, then the other twin should have one as well. Since this pattern didn't holdup, researchers deemed the G-spot a subjective fluke. However, this analysis received harsh rebuke from French scientists. Not only did the French scientists claim that about 60 percent of women possess a G-spot, they also said that the Brits were simply too uptight and "totalitarian" about sex to find it [source: Davies]. Politer dissenters also piped up to point out that while twins may share their genes, they usually don't share their sexual partners, meaning that one twin may simply have lucked out in that department [source: Roberts].

One reason researchers -- and women -- are so interested in the G-spot is that it, along with the adjacent Skene's glands, might constitute the female prostate. The male prostate is a notable erogenous zone, and some women claim that when their own prostate is stimulated, they are able to ejaculate like men. Women have volunteered to ejaculate in lab environments, and they emit a fluid that is very similar to semen, both in appearance and in chemical make-up.

It's uncertain how common female ejaculation is, and to many researchers, it's also unclear if studies of the female anatomy or the female orgasm will yield any useful information to the population as a whole because women seem to vary so widely in their anatomy and their sexual preferences. Researchers can't even figure out why women have orgasms, since conception isn't dependent on it. Theories range from the idea that a man who takes the time and effort to give a woman an orgasm is marked as a good, patient provider for future offspring to the possibility that vaginal contractions help sperm on their journey to the cervix. Female orgasms, either vaginal or clitoral, may just be a happy accident.

For now, the G-spot will remain controversial and sometimes elusive. On the next page, we'll look at another contentious part of the vaginal anatomy.

Vulvodynia

Painful sex is often a sign that the woman is not lubricated enough, but it can also signal a medical problem. Women might experience painful sex as the result of a vaginal infection, an STD or a condition known as vulvodynia. Women suffering from vulvodynia experience searing pain during sex but also when exercising or even when wearing tight pants. Doctors are still trying to understand this condition, which may be due to an overabundance of nerve endings in the genital area.

Hymens

On the last few pages, we talked about the vagina's role in sexual pleasure. Historically speaking, the idea that women could enjoy sex is a relatively new phenomenon, and even today, many girls and women are told that sexual intercourse will hurt the first time they experience it. This pain is attributed to the hymen, which covers the vaginal opening; it's very common to hear that the first penis to enter the vagina must break through this layer of skin tissue, which will typically cause pain and blood. Hymens have thus become tied to virginity, and many people believe that the presence or lack of a hymen can tell you whether or not a woman has had sex.

It's true that women may experience pain or bleeding the first time they have sex, but it's not because of their hymens; more likely, they began having intercourse without proper foreplay to lubricate the vagina. And as it turns out, hymens tell you nothing about a woman's sexual history. Not every woman is born with a hymen, and the shape and size of a hymen differs dramatically from woman to woman. Since the hymen doesn't appear to serve any purpose, it may very well be vestigial.

The hymeneal skin tissue changes and stretches over time, particularly when a girl enters puberty. Once a girl begins menstruating, there has to be some sort of hole or break in the hymen -- otherwise, menstrual blood couldn't escape the vagina, which causes serious clots. Everything from exercise to tampons can change that layer of skin -- even having sex doesn't guarantee that the membranes will go away, because the hymen is self-repairing and holes can close back up. In other words, the angst that many women feel about the state of their hymen and what it means about their virginal status is all for nothing.

Even if a woman has a mostly intact hymen at the time of her first sexual intercourse, she may not bleed. However, in some cultures, blood on the bed sheets is expected the day after a wedding because a woman's virginity is directly connected to her family's honor. For that reason, some women undergo a hymenoplasty, which is surgery to reconstruct a hymen. The surgery, in which doctors sew skin membranes to the vaginal walls, costs several thousand dollars and may not even guarantee that a woman will bleed the next time she has intercourse. The media has highlighted a diverse clientele for this procedure -- everyone from secular women in the United States who have the surgery as a present for their husbands to Muslim women in Europe who have the surgery so that they will pass a hymen check required by their potential parents-in-law. This surgery angers women's rights advocates because the idea that a hymen is a requisite for virginity simply is scientifically incorrect.

Hymen reconstruction isn't the only major surgery going on down there. On the next page, we'll take a look at the extremes some women go to in pursuit of the best vagina possible.

Eve Ensler's play "The Vagina Monologues" made many women more comfortable with their private parts.

What Does a Normal Vagina Look Like?

Women trying to restore their hymens aren't the only ones seeking surgery on their private parts. In recent years, a trend of genital cosmetic surgery has emerged, as women who are unhappy with the look or feel of their vulvas and vaginas pursue surgical options.

One of these surgical options is labiaplasty, in which a woman's labia can be made smaller or bigger, or made to more accurately match the other. While overly large labia can be a medical problem -- one that causes pain during sex or exercise -- doctors report that many of the women seeking this surgery have perfectly normal labia [source: Kantrowitz]. Other women seek surgery that will make their vaginas tighter after childbirth. While vaginas can stretch slightly during childbirth, doctors urge women to seek non-surgical options such as Kegel exercises. These exercises require a woman to squeeze the muscles of her pelvic floor to strengthen the walls of the vagina.

The concept of the "designer vagina" worries both doctors and women's rights advocates because there's no such thing as a perfect set of genitals. To borrow an overused phrase, vaginas are much like snowflakes -- no two are alike. And while some women pursue vaginal cosmetic surgery because they believe it will bring them a better sex life, impaired sexual function is often one of the unfortunate side effects, along with scarring and chronic pain. Not to mention psychological effects and poor self-esteem; it's possible that the rise of pornography has led women to believe that there's an ideal vagina when in actuality, there's not [source: Navarro].

Many women spend a lot of time worrying not about what their vagina should look like, but what it should smell like. A mild odor is normal, as is a regular amount of vaginal discharge. Normal discharge is typically clear, white or yellow, and takes a variety of forms, from fluid to clumps. Discharge is the vagina's way of cleaning itself and maintaining a healthy balance of yeast and bacteria. An over-the-counter product, such as a douche or a spray, will only ruin that balance and cause infections.

While most odor and discharge is normal, some can indicate that the vagina is infected. We'll talk about vaginal health on the next page.

Regular visits to a gynecologist for a pelvic exam will keep the vagina in tip-top shape.

Vaginal Health

Vaginitis, or a vaginal infection, is marked by redness, itching, abnormal discharge and pain in the vaginal area. A fishy or foul odor might be a sign that something's wrong. Abnormal discharge might be more abundant in quantity, chunkier or heavier than usual, or gray, green or pink in color.

There are several different types of vaginal infections. Yeast infections are caused by an overabundance of yeast in the vagina, which may be the result of antibiotics, uncontrolled diabetes, pregnancy or stress. Yeast infections are very common, but that doesn't mean that every itch in the vaginal region is a yeast infection; in fact, some studies have shown that women buying over-the-counter yeast infection medication often had a different kind of vaginitis [source: Brody]. Yeast infections are commonly mistaken for bacterial vaginosis, which is caused not by an overgrowth of yeast, but rather an overgrowth of bacteria. Bacterial vaginosis is usually accompanied by a fishy odor and is common in sexually active women, though it's not a sexually transmitted disease. Still, sexually transmitted infections can cause problems in the vaginal area -- itchiness and redness might be the result of diseases such as trichomoniasis, Chlamydia and gonorrhea. Bottom line: Head to a medical professional for an accurate diagnosis and treatment plan.

As women age, their vaginas change due to the drop of hormones that accompanies menopause. Older women are often at risk for vaginal atrophy, which is marked by vaginal dryness and thinning of the vaginal walls that result in painful intercourse. Doctors may prescribe topical estrogen treatments or simply advise women to use more lubricant during sexual activity. Aging is also a risk factor for vaginal cancer, which is not very common and usually curable. More common, and a danger to women of all ages, is cervical cancer. The risk factors for cervical cancer include infection with human papillomavirus (HPV), multiple sexual partners, smoking and oral contraceptives.

To protect and maintain vaginal health, women should see a gynecologist at least once a year after the age of 18, or as soon as they become sexually active (whichever comes first). Gynecologists perform pelvic exams and Pap tests to check on the health of the female reproductive system. And there are things women can do to take care of their vaginas on a daily basis, including wiping front to back after using the restroom, washing the labia with a gentle, unscented cleanser, keeping the vaginal area dry, avoiding overly tight clothing, practicing safe sex, and maintaining a healthy diet and exercise regimen.

Do you have more questions about sexual health and the female reproductive system? Check out the links on the next page.

Joannides, Paul. "New York Times is Wrong about the Hymen -- But They Are Not Alone." Psychology Today. June 11, 2008. (May 30, 2011) http://www.psychologytoday.com/node/979

Jones, Nicola. "Bigger is better when it comes to the G spot." New Scientist. July 3, 2002. (May 30, 2011) http://www.newscientist.com/article/mg17523503.100-bigger-is-better-when-it-comes-to-the-g-spot.html

Kolata, Gina. "Women and Sex: On This Topic: Science Blushes." The New York Times. June 21, 1998. (May 30, 2011) http://www.nytimes.com/1998/06/21/health/women-and-sex-on-this-topic-science-blushes.html

Moalem, Sharon. "Everything you always wanted to know about female ejaculation." New Scientist. May 30, 2009.

Navarro, Mireya. "The Most Private of Makeovers." The New York Times. Nov. 28, 2004. (May 30, 2011) http://query.nytimes.com/gst/fullpage.html?res=9D06E0DA123EF93BA15752C1A9629C8B63&scp=1&sq=labiaplasty&st=cse&pagewanted=print